Diazotype reproduction material and method



Feb. 10, 1959 R. P. WEEGAR ET AL 2,873,207

DIAZOTYPE REPRODUCTION MATERIAL ND METHOD Filed Feb. 21, 1955 mvENToRs:RALPH P WEEGAR HENRY C. UNKAUF United States Patent DIAZOTYPEREPRODUCTION MATERIAL AND METHOD Ralph P. Weegar, Villa Park, and HenryC. Unkauf,

Chicago, Ill., assignors to Eugene Dietzgen Co., Chicago, Ill., acorporation of Delaware Application February 21, 1955, Serial No.489,439

12 Claims. (Cl. 117-34) This invention relates to a diazotyp'ereproduction material and method o-f manufatcure. More particularly, itrelates to the provision of a light-sensitive diazotype layer onaniimpervious organic surface of a photographicbase material, especiallyin the production of a dimensie-nelly stable photographic reproductionmaterial.

Water and organi-c solvent-impervious organic surfaces such as those onpolyester-filled glass and cotton fabrics, as commonly employed in theform of sheets in the drafting and printmaking ield, pose diflicultproblems in the application and fixation thereon of other substances,particularly materials which provide photographic lightsensitive layers.

In the provision of photographic light-sensitive layers on basematerials, an absorbent surface is commonly treated with a solution oflight-sensitive components whichV serve to reproduce a desired image;Thus, for example, diazotype reproduction media are produced by treatingan absorbent surface with a solution` containing azo dye components inan uncombined form. The most commonly used base material is paper, andthe components are usually in aqueous solution. Sucient penetration isobtained to insure bonding ofthe paper and the sensitizing composition,and the ultimate dye image. Cellulose esters and ethers are also incommon use as base materials, and they are impregnated with asensitizing solution by the addition of penetrating or swelling agentswhich have a solvent action on the base material, to insure thenecessary bonding.

The prior methods are, however, unsuitable for coating or impregnating`water and organic solvent-impervious surfaces, there being insufficientbonding with the base material to provide a uniform layer of thesensitizing components which is permanently bonded and is resistant towear and abrasion. Furthermore, the dye images reproduced on the surfaceby exposure and'development have little permanency, and in order toprevent easy removal of the images, it is necessary to overcoat themwith a transparent coating. Even such a coating on, for example,polyester-impregnated glass cloth, is easily scratched, chipped andotherwise damaged in ordinary handling, shipping, and storage.

There' are a number of advantages in the use of water and organicsolvent-impervious base materials, especially those having a polyestersurface, and it is therefore highly desirable to provide reproductionmaterials which include these materials together with a light-sensitivelayer.

It is therefore an object of the invention to provide a new and improveddiazotype reproduction material and method of manufacture.

A particular object is` to provide a reproduction material whichincludes a base having a polyester surface and a light-sensitivediazotype layer thereon.

A further object is to provide a dimensionally stable diazotypereproduction element which furnishes excellent uniform permanentreproduction and which is resistant to the various conditionsencountered. An additional object'is to supply a reliable and effectivemethod for providngay light-sensitive diazotype layer on aliquid-impervious polyester surface of a photographic base material. Theimpervious surface referred to absorbs substantially no water or organicsolvent, so that it is unreceptive to aqueous and organic. solventsolutions,` for all practical` purposes, and there will be no or onlyinsubstantial adherence or binding of the solutions and theiringredients to the surface.

Another object is to coat an impervious polyester surface employing aprincipally non-aqueous organic solvent solution of a light-sensitivediazo compound.

Still another object is to provide a diazotype reproduction materialhaving a base of a polyester-filled tracing cloth, such as apolyester-filled glass or cotton fabric, and the like, and a stronglyadherent diaz-otype layer. Polyester-filled glass tracing cloth,commonly referred to as photo-template glass cloth, provides adimensionally stable reproduction material.

An additional object is to provide a method of preparing a polyestersurfaced body having a design on the surface.

Yet another object is to provide a diazotype coat on a photographic basematerial having the desired properties of transparency or translucency,little color, storage stability and resistance to chemical and physicalattack under the conditions normally encountered.

Other objectsinclude the manufacture and application of new and improvedcoating compositions, andy coats and coated base materials, and theprovision of new and useful methods. These and other objects andadvantages of theinvention will appear on consideration of thespecication taken in conjunction with the attached drawing, in which thesingle figure is a broken perspective View of photo-template glass clothprovided with a diazotype layer or coat, according to a preferredembodiment of the invention.

The invention provides a photographic reproduction material whichincludes a base material having an impervious unsaturated polyesterresin surface, and a coat of a light-sensitive diazo compound and acellulose ester or ether. To furnish a satisfactory bond with thepolyester surface, a bon-ding coat of an amine-formaldehyde resin isincluded between the polyester surface and the diazo layer or coat.

A method for providing a diazotype layer on anV impervious unsaturatedpolyester resin surface is provided in the invention, which methodincludes providing on the polyester surface a coat of anamine-formaldehyde resin and a solvent-soluble material serving toincrease the solvent sensitivity of the coat While retaining itsadhesiveness, and coating the resulting coated surface with an organicsolvent solution of a diazo compound and a cellulose ester or ether.

rlhe base material provided with a coat of an amineformaldehyde resinforms the subject matter of copending application, Serial No; 489,438,filed February 2l, 1955, by Ralph P. Weegar and Henry C. Unkauf, whichis incorporated herein by reference and made a part hereof as fully asif set forth herein in its entirety.

As `disclosed in the above copending application, it has been found thatamine-formaldehyde thermosetting resins exhibit very good adhesion topolyesters, in particular, polyester-filled fabrics, such as glass orcotton fabrics, represented by the tracing cloths in common use inthedrafting and printmaking field.

The invention has particular reference to the unsaturated polyesterresins, as the class is defined on pages S20-524 of Modern PlasticsEncyclopedia, issue/vol. 32, No. 1A, 1954. These resins are condensationproducts of dibasic acids and glycols, prepared in part from anunsaturated dibasic acid, such as maleic or furnaric acid, and a glycol,suchV as ethylene glycol. The linear'polyesteris Patented Feb. l0,19t-39:u

cross-linked with a polymerizable monomer, a monomeric vinyl typecompound such as vinyl acetate, methyl meth acrylate and styrene, toprovide a thermoset solid. Illustrative of the4 polyester resins coatedin the invention are the Paraplex polyester-styrene resins (ResinousProd-v ucts & Chemical Co.), such as P-l3 (flexible grade), P-43 (rigidgrade) and P47 (semi-rigid grade). In the preparation of flexibletracing cloth, an exemplary com- .position for filling the fabric is amixture of P-13 and P-47 in a weight ratio on the order of l to 4. Theseimpervious polyester materials are resistant to the conditionsencounteredin the production and use of photographic reproduction media.

The amine-formaldehyde resin may be a melamine, urea, urea-melamine,alkylated urea, acetylene diurea, or triazine type formaldehyde resin,for example. Preferably, a urea-modified melamine formaldehyde typeresin is employed, such as Uformite MU56 (Resinous Products & ChemicalCo.). Other `representative resins are Uformite MM-SS, a melamine resin,and MX-61, a triazine type resin. The resins are employed inheat-convertible form and are cured or thermoset on the polyestersurface.

The cured amine-formaldehyde resin may be and frequently is resistant tothe solvents which it is desired to use in the subsequent applicationofa photographic sensitizing composition, such as alcohols, ketones andesters, and incompatible with the other constituents of the sensitizingcomposition. The resin is therefore ntodied to provide a coating towhich a sensitizing layer will adhere properly without destroying theadhesion to the polyester surface. Thus, in addition to theamineforrnaldehyde resin, the coating composition and resulting coataccording to the invention include a solventsoluble material serving toincrease the solvent sensitivity of the coat while retaining itsadhesiveness. The preferred solvent-soluble materials are the esters andethers of cellulose, such as cellulose nitrate, ethyl cellulose, andcellulose acetate, and s hellac.

The resin coating compositions contain the described ingredients insolution in a suitable volatile organic solvent, lower alphatic estersbeing preferred as exhibiting good compatibility. The compositionsshould also includea curing catalyst, such as an acid. The base materialis coated and thus rendered receptive to the sensi tizing composition byapplying the solution to the surface of the material, removing solvent,and curing, preferably at a temperature of about 220-300" F.

It is further preferred to overcoat the amine resin coat, to increaseits receptivity to the outer diazo-containing coat. The overcoatcontains shellac and a member of the class of cellulose ethers andesters, such as ethyl cellulose, cellulose acetate, and nitrocellulose.The over coat is applied in volatile organic solvent solution, e. g., ina lower aliphatic alcohol or ester, the solvent is rcmoved, and theovercoat is cured, preferably at 220-300 F. Both the first coat and theovercoat are preferably cured together.

The sensitizing composition may be applied at any time after theovercoat, as described in more detail subsequently. The sensitizedproduct prepared in this man ner will then consist essentially of thebase material and three coats, films or layers on a surface thereof. ltwill be understood that these ,coats will merge and extend into adjacentareas at their inner faces due to penetration, diffusion, and the likeduring application and curing or hardening.

While the proportions of the components of the amine resin or firstcoatings are subject to some variation de' pending upon the particularcomponents and the properties sought, it is preferred that theamine-formaldehyde resin be present in a major proportion of the contentof the amine resin and solvent-soluble material. Preferably, thesolvent-soluble material, e. g., cellulose ester, cellulose ether orshellac, is present in a proportion of about 4. -80% by weight of theamine resin, and it is further preferred that the proportion be about15-60%.

To improve the properties of the amine-formaldehyde resin coating, analkyd resin, in particular, a non-oxidizing pure phthalic alkyd resin,may be incorporated into the compositions. The alkyd resins arepreferably cured or thermoset pure phthalic alkyd resins modified with anon-drying oil acid, especially those of the glycerol phthalic anhydridetype. Thus, for example, the alkyd resins may be the reaction productsof phthalic acid or halogenated phthalic acid with a trihydric alcoholsuch4 as glycerol or other alcohols having three or more hydroxylgroups, or their hydroxyalkyl ethers, modified with i a nondrying oilacid such as the acids of coconut oil,

castor oil, cottonseed oil, olive oil, and the like. The preferred resinis a cured coconut oil acid-modified glycerol phthalate resin. When thealkyd resin is mixed with the heat-convertible amine-formaldehyde resinand the mixture is cured on the polyester surface, the resins adherestrongly and have a very pale color which is retained during and aftercuring.

In this preferred composition, the alkyd resin is employed in an amountequivalent to about Sil-200% by weight of the amine-formaldehyde resin,ldepending on the particular properties sought. An especiallyadvantageous coat on phototemplate glass cloth is obtained when aboutISO-200% by weight of alkyd resin is used, based on the amine resin.Employing both resins, the proportion of solvent soluble material is asdescribed above for the amine resin alone, but the proportion is basedinstead on the combined weight of the alkyd and amine TCSIUS.

In the above first overcoat, which is applied over the amine resin oramine resin-alkyd resin coat, shellac is the predominant ingredient,about l050% by weight based on the shellac of cellulose ester or etherbeing included, with l5-25% of the latter being further preferred.

It may also be of advantage to provide a second overcoat, on the surfaceof the first and between it and the sensitizer coat. This embodiment isthat illustrated in the drawing. The second overcoat contains an acrylicester resin and a cellulose ester or ether, preferably nitrocellulose.The most useful acrylic esters are the methyl and ethyl esters ofacrylic acid and methacrylic acid. The resins employed belong to theclass of soft resins soluble in petroleum hydrocarbons. Ethyl acrylateappears to provide the most suitable resin. An exemplary resin isAcryloid F-lO (Resinous Products & Chemical Co.), a mineral thinnersoluble acrylic ester resin.

The second overcoat preferably contains a. Vmajor weight proportion ofthe cellulose derivative, based on the total of the latter and theacrylic ester resin. It is further preferred that the proportion ofacrylic ester resin be about 25-50% by weight based on the cellulosederivative. The second overcoat is applied to the first overcoahaftercuring the latter, in a volatile organic solvent solution of thepolymerized acrylic ester and the cellulose derivative, preferably in alower aliphatic ester. The coated material is then dried to removevolatiles, preferably at about 15C-175 F.

The polyester surface thus coated and rendered receptive to thesensitizing composition is provided with an outer layer or coating of alight-sensitive diazo compound and a cellulose ester or ether, byapplying the components in an organic solvent solution. A clear,colorless film-forming cellulose ether or ester is ernployed, such asethyl cellulose, cellulose acetate, and nitrocellulose.

An important phenomenon cooperating in the invention is that althoughthe films of the cellulose derivatives are not alone pervious to ammoniaand water vapor, and to the developing solutions, so that a diazo layercannot be overcoated satisfactorily with them, the thin films aresuiciently pervious when mixed with the diazo com-y those which areN-rnono or (li-substituted `on the undiazotized amino groups, with orwithout aliphatic substitution on .the benzene ring. Also included areresinous condensation products of aldehydes, such as formalde- `hyde,with these light-sensitive `diazo compounds, and the p-amino phenylsulfones of the diazo compounds. The boron tritluoride, the stannouschloride, the cadmium chloride, `and `thezinc chloride double salts ofthe afore- `mentioned light sensitive `organic solvent soluble 'diazocompounds are included. Specic examples of such jcompounds which areusedin the `production `of diazotype images of high contrast are thediazo derivatives of p-amino-N-methyl aniline, p.-amino-N-di-methylaniline, p-amino-N-ethyl aniline, p-amino-N-di-ethyl aniline,pamino-NmethylNethyl aniline, p-amino-N-ethoxy anidine,p-aminoNmethyl-N-ethoxy aniline, p-amino-N- ethyl-N-ethoxy aniline,pamino-N-diethyl-m-toluidine, and 1-amino-3-methyl-4-ethylamino benzene,all in the form of their diazo double salts with zinc chloride, `cadmiumchloride, stannous chloride,.or.boron triuoride, or their .diazop-amino-phenyl sulfones, `or their diazoformaldehyde resinouscondensation products.

As coupling components, any compound which will f'function as a couplingcomponent may be employed .either inthe coating composition togetherwith the diazo .compound in order to produce a two-component system, ,orin the developing solution asa color forming developer. In either case,the coupling component selected `iwillibe one which will `produce thedesired `color or a combination of coupling components which willproduce a multi-color effect. Examples of preferred coupling 4componentsare: 2,3-dihydroxy naphthalene and its `6- .sulfonic acid derivative,phloroglucinol, methyl Aphloroglucinol, resorcinol,lresorcinol-mono-methyl `ether, di-

-chloro .resorcinol, r11-hydroxy phenyl urea, acetoacetanilide,`acetoacetylcyclohexyl amide, 7-hydroxy naphthaamino-8-naphthol3,6disulfonic acid, 2,7 dihydroxy naphthalene, l-naphthol-l-sulfonic acid,and l-amino-S- The sensitizing compositions may contain 'the usual`adjuncts ysuch as metal salts, to intensify the dyestuil` image, i.`e., aluminum sulfate, titanium ammoniumfluoride, nickel sulfate and`the like, and acids designed to =retard precoupling such as citricacid, maleic acid, tar- `taric acid, `boric -acid and the like.

.T he diazo composition. can also. advantageously include a V'fillersuch as colloidal silica, hydrated silica, diatomaceous earth,bentonite, mica and the like. The filler `acts to raise the softeningpoint of the coating, promote development of aprint by inducingporosity, and provide a mat surface.

The sensitizingcomposition is a principally non-aqueous organic solventsolution of the diazo ingredients and .the cellulose ester or `ether.The ingredients are balanced for mutual compatibility and the propertiesdef-sired. The solvent and cellulose derivativeare selected forsolubility and are adjusted to a viscosity suitable `for application andwhich` will properly suspend the ller, and to provide a continuous`ilexible abrasion-resistant iiilm.v The solvents are preferablyselected from the `group of-lower aliphatic alcohols, lower aliphaticketones, lower aliphatic glycol esters and lower aliphatic glycol`ethers, and they are specially `selected to furnish a controlled rateof drying on application to the base material. Thus, thesolvents are`balanced toresult in a drying rate Awhich "is slow 4'enough to avoidcondensation orlpic'kup rof water and to avoid ,premature drying lin therollers -or other equipment, yet rapid enough to dry rapidly andcompletely in a satisfactory manner after application, furnishing a thinuniform strongly adhering and )nontacky surface coat. For example, adrying rateof 5-10 minutes `at 150-175" F. in commercial coatingequipment is provided.

`The primary solvent for the mixture is methanol or ethanol, or acetoneor methyl ethyl ketone may be Vsubstituted in whole or in part. Theprimary solventlis present in a major proportion by `weight of the total'ofthe organic solvents, preferably in a proportion of -90% of thesolvents. The primary solvent 'is blended with a minor proportion,preferably lO-40%, of a higher boil ing alcohol or theequivalent, whichserves to Aprevent overly rapid drying with consequent blushing Themedium boiling lower aliphatic alcohols `having 4 carbon atoms or moreand which are liquid at room temperature, such as butyl alcohol and amylalcohol, are desirably employed, and they Ymay be substituted in wholeor "in part by lower aliphatic glycol esters or ethers, such as theesters or ethers of ethylene glyool, propylene yglycol and glycerine. Ina controlled low humidity, normal or isopropanol may be used alone. lnthe selection of solvents, due consideration must be given to thesolubility of the .cellulose derivative.

rprinting, afsmallamount of a lower aliphatic glycolfsuch asethylene-glycol, propylene .glycoland glycerine, may

be included to `assist in picking up Water vaporin developing. Theproportion of Vglycol is preferably about 1A Ito l part by weight to lpart of the cellulose derivative. This function together with'that ofthe secondary or 4higher boiling solvent is also provided `by`cellosolve esters, such as the lower aliphatic cellosolve esters,preferably -alkoxy ethyl acetate. p

'In the sensitizing composition, the cellulose ether or ester binder ispreferably employed in a proportion of about 1A to 5 parts by weightto lpart of diazo compound. The reference to diazo .compound does n-otinclude the coupling components ,and the adjuncts. About 20 to 20()parts by Weightfofsolvent are employed-per part of diazo compound, soVthat-the diazo oompoundis present in a proportion of aboutS toil-5% `ofthe solvents.

About 30to dt'lparts iof'solvent `per'part ofthe cellulose binderareemployed,equivalent to a `proportion'ofbind'er 4'of about 3.3% toA1.6% lbased `on the solvents. 'It-is ordinarily` preferred toincorporateabout 0.5 tto v5 tparts of `filler per part of diazocompound.

The composition includes merely sufficient water to dissolve thosecomponents of the diazo system which are insoluble or diicultly solubleinorganic solvents, but not enough to precipitate the cellulose ester`or ether binder, and the proportion of water thus amounts to a maximumof about 3% `byweight ofthe complete sensitizing comi position.

The sensitizing composition prepared'inltheabove manrieris applied tothe polyester surface whichhas been rendered receptive thereto by theapplication of the described amine-formaldehyde resin coat, by brushing,

spraying, bead-coating, rollercoating, silk screeningyor thelike, toprovide a thin coat on `the surface. `Thematerial is dried in the'dark,at.ajtemper.ature of fromabout room temperature to about 250 F., theupper temperature being limited bythe stability of the diazo components.An adherent sensitized layer is thus firmly bonded to the polyestersurface. Thephotographic reproduction materialrso produced canfbeexposed "to light of `varying intensity in accordance with a `design`tobe reproduced thereon, e. g., under a pattern to be'reproduced, and theimages developed by exposure to ammonia vapors in the case of thetwo-component or dry-developing process, or by spraying, dipping,swabbing or sponging with a developing solution in the case of theone-component or moistdeveloping process.

When the original pattern or drawing is produced on a dimensionallystable medium, such as photo-templateglass cloth, the final diazotypereproduction will be an exact true-to-scale duplicate copy of theoriginal. The resulting copy is unaffected by atmospheric moisture andcontinues to maintain its dimensional stability during handling andstorage. The duplicate copy requires no overspraying or lacquering, asthere is no rubbing or peeling l,off of the surface, and the image iswell protected. The reproduction materials and the resulting prints maybe transported and employed in various localities, for example, theyhave found widespread application in the manufacture of metal templatesin the aircraft industry.

The following examples are furnished to assist in providing a completeunderstanding of the invention, but it lis to be understood that theinvention is not limited thereto nor to the specific compositions,proportions and conditions set forth therein, which are given only forpurposes of illustration.

Example 1 The following composition is employed to provide anamine-formaldehyde resin layer on an impervious polyester surface:

Urea melamine formaldehyde resin (Uforrnite MU-56) gm 130 5-6 Second RSnitrocotton gm 20-100 Ethyl acetate cc-- 900 n-Butyl acetate- N* l()Phosphoric acid gm-- 4 Example 2 Another exemplary composition is thefollowing: Urea-melamine-formaldehyde resin (Uformite MU-56) gm-- 130Ethyl cellulose gm-- 20-100 Ethyl acetate CC-.. p 900 n-Butyl acetatecc.- 100 Phosphoric acid s gm 4 The coat is applied as-in Example 1 andis cured for about 5 minutes at Z50-300 F.

Example 3 An additional composition wherein an alkyd resin is included,is the following:

Cured, non-drying oil acid-modified pure phthalic alkyd resin gm 130Urea-melamine-formaldehyde resin gm-.. 50-130 1/2 second RS nitrocottongm. 50-150 Ethyl acetate cc 900 n-Butyl acetate rt 100 Ethyl phosphoricacid gm..- 8

The coat is applied as in Example 1 and is cured for about 5 minutes atZ50-300 F.

Example 4 The following is an example of a composition for providing anovercoat on the surface of the coat formed according to Examples 1-3:

8 Bleached, dewaxed shellac gm..- 125 5-6 Second RS nitrocotton gm-..15-50 Ethyl acetate cc-- 200 Methanol cc 700 n-Butanol cc Example 5Another example of a composition for providing an overcoat to furtherincrease the receptivity of the alkyd resin coat is as follows:

Bleached, dewaxed shellac ..-gm

Ethyl cellulose gm-.. 15-50 Ethyl acetate cc 2.00

Methanol cc-- 700 n-Butanol cc-- 100 Example 6 The following compositionis applied by roller coating commercial photo-template glass cloth witha layer which is 0.0002-0.0004" thick.

Cured coconut oil-modilied trihydric alcohol-phthalic anhydride alkydresin (Duraplex ND-77B, Resinous Products & Chemical Co.) -grn--Urea-melamine-formaldehyde resin (Uformite MU- 56) 9m. 75 5-6 Second RSnitrocotton ..-gm.... 75 Hydrated silica gm-- 5() Ethyl acetate cc-- 900n-Butyl acetate cc 100 Ethyl phosphoric acid 2m 10 position:

Bleached, dewaxed shellac gm-.. 100 5-6 Second RS nitrocotton gm-.. 20Hydrated silica gm-.. 50 Ethyl acetate cc 200 Methanol cc 700 n-Butanolcc- The overcoated product is dried at about ISO- F. for tive minutes,and the combined coatings are cured at about Z50-300 F. for ve minutes.

The resulting coated photo-template glass cloth is receptive to alight-sensitive diazotype organic solvent composition, which is appliedthereover as described in the subsequent examples.

Example 7 A second overcoat may be applied on the surface of the firstovercoat of Example 6. The following composition is applied and dried inthe same manner aspthe first overcoat:

(Acryloid F-10) gm- 5-6 Second RS Nitrocotton gm 20-40 Ethyl acetate .cc600-800 n-Butyl acetate ec-- l00-300 -methoxy ethyl acetate (Carbide &Carbo methyl cellosolve acetate) cc-- 100-300 `Water cc The resultingcoated photo-template [glass l'cl'oth is ref ceptve to a light-sensitivediazotype organic solventco'mposition, which is applied thereover asdescribed in the subsequent examples. The complete"photographic-reproduction material or element, lillustratedfin `thedrawing, then includes the sheet of .photo'ltemplate `cloth 1, ltheam'ine resin-alkyd Aresin coat adhering to a surface of the cloth, theintermediate shellac rstoverc'oat 3 adhei-ing to the outer surface oftheresin coat .2, the `intermediate `acrylic ester resin second overcoat!'adhering to theouter surface of the `shellac overcoat 3, and 4the outerse'nsitizing coat S adhering :to the outer surface of the acrylic esterresin coat 4. The acrylic ester ,resin "Second overcoat 4` may beomitted, so `thatthe sensitizing coat 5 adheres to the outer surface ofthe shellac Aovercoat 3.

Example 8 lIhis example illustrates the production Aof a (direct(p'ositive image) dimensionally stable sepia intermediate '(secondoriginal) print,\am1nonia developed, on phototemplate `glass cloth.

A solution of sensitizer is prepared, having ,the rfollow- -ingcomposition: i

These ingredients, thoroughly mixed and ltered, are added to thefollowing mixture: t

Methanol cc 8000 n-Butanol cc 1600 Silica aerogel (Monsanto Santocel CX)gms 600 `ethyl cellulose `in methanol (Hercules "N-SO) cc `6000 .t Thenal sensitizing solution islstored ina covered crock `until ready foruse.

`A roll of commercial plastic-impregnated photo-template glass cloth, 36wide, 0.005 thick, ZOO-yards long, iswsub-coated according to Example6er 7 and is then `bead-coated in a layer about 0.000l-0.0002 thick withtheabove-described sensitizing solution on acloth llacquering machine ofconventional design, dried in the dark, and Wrapped andpackaged in yardlength rolls. Using part of one of these rolls, a contact print ismadeby means of a carbon arc light and a vacuum frame, on av 3 x A12 sectionof the sensitizedmaterial. As the original pattern, a 3 x l2non-dimensioned engineering pencil drawing on plastic-impregnated glasstracing cloth is used.

The resulting sepia intermediate `(or second original print, ammoniadeveloped is an exact, true-to-scale posi- Vtive copy of the originalpencil drawing on` glass cloth, p having a verytsmall linear distortion.From this tsecond original copy `can now be made exact true-toscalenondimensioned `metal template, if `the `metal has been sensitized witha positive image printing type of sensitizer- Example 9 This exampleillustrates the production of a direct (positive image) dimensionallystable blue line print, ammonia developed, on photo-template glasscloth.

A lsolution is prepared, having the following composi tion: t v

1Methanol cc 3500V pn-Butanol cc 250 150y egfsvsgfoe in o Ethyleneglycol cc `150 Citric acid gms 100 Zinc chloride gms t Urea fgms 1.002,3-difhydroxynaphthalene grns Z 1p+diazofN-ethylfNethoxy aniline,stannous chloride douole salt gms 150 added to the following mixture:

Methanol -c 21000 An-Butan'ol cc` `800 'Hydrated silica 'gms 300 Ethylcellulose 10% solutionin methanol. cc '3000 A roll ofplastic-impregnated photo-template glass cloth, 48 wide, 0.005 thick,150 yards long, is subcoated according to Example `i6 yor 7 and. is thenrollercoatedin a layer yabout 00001-00002 `thick with `theabove-described'sensitizing solution on a cloth lacqucring machine ofconventional design, dried in the dark, and wrapped and packaged insheets 4' wide and lin Alengths from 4 to l2'. A 4 x 8 sensitized sheetis selected, and a print is made from a 4 x 8 second original sepiaintermediate print on plastic-impregnated glass eloth (made `from a'non-dimensioned,` vtrue-to-'scale rengirneering `drawing `onphoto-template glass .cloth hy the method `described inExample `f5).

The 4resulting blueline `positive copy, `printed :and ammonia developed,is an exact, true-to-scale positive copy `of `the second original sepiaintermediate print, `having a very small linear distortion. i

Example 10 `A `solution 'is prepared, having the following corn'position:

A-Metboxy ethyl acetate (Carbide & Carbon methyl cellosolve acetate) cc2500 Acetone -cc 500 n-Butanol cc A250 Methanol a cc 500 Water cc 300Oxalic acid f t .t t gms 100 Naphthalene 1,3 ,6-tr' s u l f o ni c acid,(sodium salt) i gms `200 ,pDiazo-N-ethylN-benzyl aniline, cadmiumchloride double salt.V gms-- 3.00

These ingredients, thoroughly mixed and filtered, `are `added to thefollowing mixture:

Methanol cc 2000 Acetone cc 2000 Silica aerog-el (Godfrey L. CabotCab-O- `Sil) t gms y1100 `Cellulose acetate (Hercules, FM grade,`56%acetic acid content) gms A roll of plastic-impregnated photo-templateglass cloth, 42" wide, 0.005 thick, 100 yards long, is subcoatedaccording to Example 6 or 7 and is then rollercoated with theabovedescribed sensitizing solution on a 4cloth lacquering machine ofconventionaldesign, -dried a developing solution composed of thefollowing ingredients:

Water ce 4000 Potassium metaborate gms 300 Urea v gms 60 Phloroglucinolgms Resorcinol gms 30 After the print is developed, it is rinsed inwater and air dried. The resulting sepia line positive print on glasscloth is an exact, true-to-scale positive copy of the original inkdrawing on glass cloth, having a very small linear distortion. From thissecond original print can now be made exact, true-to-scale copies oudiazo sensitized glass cloth (as described in Example 9), or on metaltemplates when sensitized with a positive image printing type ofsensitizer.

Example Il This example illustrates the production of a direct (positiveimage) dimensionally stable black line print, semi-moist developed, onphoto-template glass cloth.

A solution is prepared, having the following composition:

-Ethoxy ethyl acetate (Carbide & Carbon cello- 10% ethyl cellulosesolution in methanol cc 3000 A roll of plastic-impregnatedphoto-template glass cloth 30" wide, 0.005 thick, and 125 yards long, issubcoated as described in Example 6 or 7 and is then offsetroller-coated with the above-described sensitizing solution on a clothlacquering machine of conventional design, vdried in the dark, andwrapped and packaged in sheets measuring 21/2 x 5'. A print is made onone of these sensitized sheets from a 21/2"x 51 second originalmoist-developed sepia intermediate print on phototemplate glass clothproduced by the method described in Example l0. For exposure, a carbonare light is used, and the direct process positive print is made by thecontact method, using a vacuum frame. The resulting print is developedby swabbing with a sponge moistened with a developing solution preparedas follows:

After the print is developed, it is blotted dry between filter papers,and air dried. The resulting black line `semi-moist developed positiveprint on photo-template glass cloth is an exact, true-to-scale copy ofthe sepia interrnediate print on glass cloth, it having a very smalllinear distortion.

ln the foregoing examples, various combinations of light-sensitive diazocompounds, or light-sensitive diazo compounds and azo couplingcomponents, soluble in the types of organic solvents described, andsuitable for the 4preparation of photographic light-sensitive layers, i.e., `which will provide a photographic reproduction, visually 12reproducing a drawing on exposure to light .and develop ing byundergoing asubstantial color change, can be substituted for thecompounds employed. Likewise, the compositions and procedures can bevaried in other ways while still providing the results of the inventionand falling within its scope.

In this manner, the invention provides a new and iml proved diazotypephotographic reproduction material, especially a material useful inapplications where dimensional stability is required. The new materialsare exceptionally versatile in their application, overcome the priordisadvantages and provide new and improved industrial applications.

What is claimed is:

1.` The method for providing a light-sensitive diazotype layer on animpervious unsaturated polyester resin surface of a photographic basematerial which comprises providing on said surface a coat of anamine-formaldehyde resin anda solvent-soluble material serving toincrease the solvent sensitivity of the coat while retaining itsadhesiveness, providing on said coat an overcoat of shellac and a memberselected from the class consisting of cellulose esters and celluloseethers, and applying to the coated surface a coat of a light-sensitivediazo compound and a member of the class consisting of cellulose estersand ethers.

2. The method for providing a light-sensitive diazotype layer on animpervious unsaturated polyester resin surface of a photographic basematerial which comprises coating said surface with an organicsolventsolution of a heat-convertible amine-formaldehyde resin and asolvent-soluble material serving to increase the solvent sensitivity ofthe coat while retaining its adhesiveness, removing volatiles, coatingthe coated surfacewith an organic solvent solution of shellac and amember selected from the class consisting of cellulose esters andcellulose ethers, curing the coating, and coating the coated surfacewith an organic solvent solution of a light-sensitive diazo compound anda member of the class consisting of cellulose esters and ethers.

3. The method for providing a light-sensitive diazotype layer on animpervious unsaturated polyester resin surface of a photographic basematerial which comprises coating said surface with an organic solventsolution of a heatconvertible amine-formaldehyde resin and a curednondrying oil acid-moditied phthalic alkyd resin and a solventsolublematerial from the class consisting of cellulose esters, cellulose ethersand shellac, removing volatiles, coating the coated surface with anorganic solvent solution of shellac and a member selected from the classconsisting of cellulose esters and cellulose ethers, curing thecoatings, and coating the thus coated surface with an organic solventsolution of a light-sensitive diazo compound and a member of the classconsisting of cellulose esters and ethers.

4. The method for providing a light-sensitive diazotype layer on animpervious unsaturated polyester resin surface of a photographic basematerial which comprises providing on said surface a coat of anamine-formaldehyde resin and a non-drying oil acid-modified phthalicalkyd resin and a solvent-soluble material from the classconsisting ofcellulose esters, cellulose ethers and shellac, a lirst overcoat ofshellac and a number selected from the class consisting of celluloseesters and cellulose ethers, a second overcoat of an acrylic ester resinand a member selected from the class consisting of cellulose esters andcellulose ethers, and an outer coat of a light-sensitive diazo compoundand a member of the class consisting of cellulose esters and ethers.

5. rThe method for providing a light-sensitive diazotype layer on animpervious unsaturated polyester resin surface of a photographic basematerial which comprises providing on said surface a coat of anamine-formaldehyde resin and a non-drying oil acid-modified phthalicalkyd resin and a solvent-soluble material serving to increase thesolvent sensitivity of the coat while retaining its adhesiveness,providing on said coat an overcoat of shellac and a member selected fromthe class consisting of cellulose esters and cellulose ethers, andcoating the coated surface with an organic solvent solution of alightsensitive diazo compound and a member of the class consisting ofcellulose esters and ethers dissolved in a solvent selected from theclass consisting of lower aliphatic alcohols, lower aliphatic ketones,lower aliphatic glycol esters, and lower aliphatic glycol ethers.

6. The method for providing a light-sensitive diazotype layer on animpervious unsaturated polyester resin surface of a photographic basematerial which comprises providing on said surface a coat of anamine-formaldehyde resin and a non-drying oil acid-modified phthalicalkyd resin and a solvent-soluble material from the class consisting ofcellulose esters, cellulose ethers and shellac, a rst overcoat ofshellac and a member selected from the class consisting of celluloseesters and cellulose ethers, and a second overcoat of an acrylic esterresin and a a member selected from the class consisting of celluloseesters and cellulose ethers, and coating the coated surface with anorganic solvent solution of a light-sensitive diazo compound and amember of the class consisting of cellulose esters and ethers, saidsolvent being a mixture of methanol and butanol and containing a smallamount of a lower aliphatic glycol.

7. The method for providing a light-sensitive diazotype layer on animpervious unsaturated polyester resin surface of a photographic basematerial which comprises providing on said surface a coat of aurea-melamineformaldehyde resin and a coconut oil acid-modifiedtrihydric alcohol phthalate alkyd resin and nitrocellulose, a rstovercoat of shellac and nitrocellulose, a second overcoat of an acrylicester resin and nitrocellulose, and an outer coat of a light-sensitivediazo compound and ethyl cellulose.

8. A photographic base material having an impervious unsaturatedpolyester resin surface, a coat on said surface of an amine-formaldehyderesin and a solvent-soluble material serving to increase the solventsensitivity of the coat while retaining its adhesiveness, anintermediate coat of shellac and a member selected from the classconsisting of cellulose esters and ethers, and an outer coat of alight-sensitive diazo compound and a member selected from the classconsisting of cellulose esters and ethers.

9. A photographic base material having an impervious unsaturatedpolyester resin surface, a coat on said surface of an amine-formaldehyderesin and a member selected from the class consisting of celluloseesters, ce1- lulose ethers, and shellac, an intermediate coat of shellacand a member selected from the class consisting of cellulose esters andethers, and an outer coat of a lightsensitive diazo compound and amember selected from the class consisting of cellulose esters andethers.

l0. A photographic base material having an impervious unsaturatedpolyester resin surface, a coat on said surface of an amine-formaldehyderesin and a non-drying oil acid-modified phthalic alkyd resin and amember selected from the class consisting of cellulose esters, celluloseethers, and shellac, an intermediate coat of shellac and a memberselected from the class consisting of cellulose esters and ethers, andan outer coat of lightsensitive diazo compound and a member selectedfrom the class consisting of cellulose esters and ethers.

11. A dimensionally stable diazotype photographic reproduction materialcomprising photo-template glass cloth, Y

a coat adhering to a surface thereof of an amine-formaldehyde resin anda non-drying oil acid-modified phthalic alkyd resin and a memberselected from the class consisting of cellulose esters, celluloseethers, and shellac, an intermediate coat of shellac and a memberselected from the class consisting of cellulose esters and ethers, andan outer coat of a light-sensitive diazo compound and a member selectedfrom the class consisting of cellulose esters and ethers.

12. A dimensionally stable diazotype photographic reproduction materialconsisting essentially of photo-template glass cloth, a coat adhering toa surface thereof of a urea-melamine-formaldehyde resin and a coconutoil acid-modified trihydric alcohol phthalate alkyd resin andnitrocellulose, a first overcoat of shellac and nitrocellulose adheringto the outer surface of the first-named coat, a second overcoat of 4anacrylic ester resin and nitrocellulose adhering to the outer surface ofthe first overcoat, and an outer coat of a light-sensitive diazocompound and ethyl cellulose adhering to the outer surface of the secondovercoat.

References Cited in the iile of this patent UNITED 'STATES PATENTS1,756,400 Schmidt Apr. 29, 1930 1,947,160 Holzwarth Feb. 13, 19341,997,745 Renker Apr. 16, 1935 2,140,089 Marasco Dec. 13, 1938 2,433,515Jahoda Dec. 30, 1947 2,606,117 Trojnar Aug. 5, 1952 2,616,803 RavichNov. 4, 1952 2,663,640 Reichel et al Dec. 22, 1953 2,698,240 Alles et alDec. 28, 1954 2,718,476 Eichorn Sept. 20, 1955

